Hereinbefore, there have been proposed various methods for treating waste water, in which waste water is converted to pollution-free water by removing the color and COD components from the waste water. Among them, massive-lime method and coagulation methods using coagulants, such as aluminium salts, iron salts or magnesium salts, have been known as relatively effective methods. However, such coagulation methods have such disadvantages that the removal of color and COD components from waste water is not sufficient and the sedimentation properties of produced flock is bad. One of the most serious problems in such coagulation methods is a problem of treatment of produced sludge. In the coagulation methods, the coagulant is separated as a sludge containing pollutant. The sludge thus obtained is of a poor dehydration property and very difficult to handle. When burning up, the cost is very expensive, and when dumping, the places therefor are restricted in view of secondary pollution.
An object of the present invention is to overcome such disadvantages of conventional methods.
Another object of the present invention is to provide a novel method for treating waste water in which the color and COD components are effectively removed and sludge is not substantially produced or, if any, the amount thereof is a little.
A further object of the present invention is to provide a novel method for treating waste water in which the treatment of waste water using inorganic adsorbent is conducted more effectively and economically.
Other objects and advantages of the present invention will more clearly appear from the following description.